The idea behind the Essential Plan, unveiled this fall, is to capture those people who might have decided not to buy health insurance because it was still too expensive even with a federal subsidy or who struggled to pay their monthly premiums and deductibles. State officials have estimated the new plan will affect about 470,000 New Yorkers, about half of whom would have been otherwise eligible for a health plan on the exchange with a subsidy. The other half would have been eligible for Medicaid or were uninsured.

To qualify for the Essential Plan, the person must earn between 139 percent and 200 percent of the federal poverty level — or no more than $23,540 for a single person and $48,500 for a family of four. It also includes low-income immigrants who have been in the United States legally for less than five years and are not eligible for federal Medicaid.

Premiums will be between $0 and $20 per adult a month and there are no deductibles. The state said the plan will cost $2.6 billion for 2016-17, $2 billion of which will be paid for by the federal government.

Becca Telzak, director of health programs for Make the Road New York, a nonprofit that serves the Latino community, said about a quarter of the 180 enrollees at its Long Island office in Brentwood have qualified for the Essential Plan, about 30 percent of whom had previously been in a regular exchange plan.

Gwen O’Shea, chief executive of the Health & Welfare Council of Long Island, said about a fifth of those who have enrolled through them so far have qualified for the Essential Plan. She said about two-thirds of those were previously enrolled in a qualified health plan from the exchange, and a little more than a quarter had been uninsured. The rest, she said, had previously been covered by Medicaid.

Stacy Villagran, head of the navigator program for the Nassau-Suffolk Hospital Council, said 17 percent of the 522 people whom the council helped sign up for health insurance last month qualified for the Essential Plan.

“I think this gives them a big break,” she said. “These are people in the lower end of middle income and you usually don’t see that group getting too many breaks.”